Metamath Proof Explorer


Theorem mcubic

Description: Solutions to a monic cubic equation, a special case of cubic . (Contributed by Mario Carneiro, 24-Apr-2015)

Ref Expression
Hypotheses mcubic.b φ B
mcubic.c φ C
mcubic.d φ D
mcubic.x φ X
mcubic.t φ T
mcubic.3 φ T 3 = N + G 2
mcubic.g φ G
mcubic.2 φ G 2 = N 2 4 M 3
mcubic.m φ M = B 2 3 C
mcubic.n φ N = 2 B 3 - 9 B C + 27 D
mcubic.0 φ T 0
Assertion mcubic φ X 3 + B X 2 + C X + D = 0 r r 3 = 1 X = B + r T + M r T 3

Proof

Step Hyp Ref Expression
1 mcubic.b φ B
2 mcubic.c φ C
3 mcubic.d φ D
4 mcubic.x φ X
5 mcubic.t φ T
6 mcubic.3 φ T 3 = N + G 2
7 mcubic.g φ G
8 mcubic.2 φ G 2 = N 2 4 M 3
9 mcubic.m φ M = B 2 3 C
10 mcubic.n φ N = 2 B 3 - 9 B C + 27 D
11 mcubic.0 φ T 0
12 1 sqcld φ B 2
13 3cn 3
14 mulcl 3 C 3 C
15 13 2 14 sylancr φ 3 C
16 12 15 subcld φ B 2 3 C
17 9 16 eqeltrd φ M
18 13 a1i φ 3
19 3ne0 3 0
20 19 a1i φ 3 0
21 17 18 20 divcld φ M 3
22 21 negcld φ M 3
23 2cn 2
24 3nn0 3 0
25 expcl B 3 0 B 3
26 1 24 25 sylancl φ B 3
27 mulcl 2 B 3 2 B 3
28 23 26 27 sylancr φ 2 B 3
29 9cn 9
30 1 2 mulcld φ B C
31 mulcl 9 B C 9 B C
32 29 30 31 sylancr φ 9 B C
33 28 32 subcld φ 2 B 3 9 B C
34 2nn0 2 0
35 7nn 7
36 34 35 decnncl 27
37 36 nncni 27
38 mulcl 27 D 27 D
39 37 3 38 sylancr φ 27 D
40 33 39 addcld φ 2 B 3 - 9 B C + 27 D
41 10 40 eqeltrd φ N
42 37 a1i φ 27
43 36 nnne0i 27 0
44 43 a1i φ 27 0
45 41 42 44 divcld φ N 27
46 1 18 20 divcld φ B 3
47 4 46 addcld φ X + B 3
48 5 18 20 divcld φ T 3
49 48 negcld φ T 3
50 3nn 3
51 50 a1i φ 3
52 n2dvds3 ¬ 2 3
53 52 a1i φ ¬ 2 3
54 oexpneg T 3 3 ¬ 2 3 T 3 3 = T 3 3
55 48 51 53 54 syl3anc φ T 3 3 = T 3 3
56 24 a1i φ 3 0
57 5 18 20 56 expdivd φ T 3 3 = T 3 3 3
58 3exp3 3 3 = 27
59 58 a1i φ 3 3 = 27
60 6 59 oveq12d φ T 3 3 3 = N + G 2 27
61 41 7 addcld φ N + G
62 2cnd φ 2
63 2ne0 2 0
64 63 a1i φ 2 0
65 61 62 42 64 44 divdiv32d φ N + G 2 27 = N + G 27 2
66 41 7 addcomd φ N + G = G + N
67 66 oveq1d φ N + G 27 = G + N 27
68 7 41 42 44 divdird φ G + N 27 = G 27 + N 27
69 67 68 eqtrd φ N + G 27 = G 27 + N 27
70 69 oveq1d φ N + G 27 2 = G 27 + N 27 2
71 7 42 44 divcld φ G 27
72 71 45 62 64 divdird φ G 27 + N 27 2 = G 27 2 + N 27 2
73 65 70 72 3eqtrd φ N + G 2 27 = G 27 2 + N 27 2
74 57 60 73 3eqtrd φ T 3 3 = G 27 2 + N 27 2
75 74 negeqd φ T 3 3 = G 27 2 + N 27 2
76 71 halfcld φ G 27 2
77 45 halfcld φ N 27 2
78 76 77 negdi2d φ G 27 2 + N 27 2 = - G 27 2 - N 27 2
79 55 75 78 3eqtrd φ T 3 3 = - G 27 2 - N 27 2
80 76 negcld φ G 27 2
81 sqneg G 27 2 G 27 2 2 = G 27 2 2
82 76 81 syl φ G 27 2 2 = G 27 2 2
83 71 62 64 sqdivd φ G 27 2 2 = G 27 2 2 2
84 45 62 64 sqdivd φ N 27 2 2 = N 27 2 2 2
85 41 42 44 sqdivd φ N 27 2 = N 2 27 2
86 85 oveq1d φ N 27 2 2 2 = N 2 27 2 2 2
87 84 86 eqtr2d φ N 2 27 2 2 2 = N 27 2 2
88 4cn 4
89 88 a1i φ 4
90 expcl M 3 0 M 3
91 17 24 90 sylancl φ M 3
92 37 sqcli 27 2
93 92 a1i φ 27 2
94 sqne0 27 27 2 0 27 0
95 42 94 syl φ 27 2 0 27 0
96 44 95 mpbird φ 27 2 0
97 89 91 93 96 divassd φ 4 M 3 27 2 = 4 M 3 27 2
98 29 a1i φ 9
99 9nn 9
100 99 nnne0i 9 0
101 100 a1i φ 9 0
102 17 98 101 56 expdivd φ M 9 3 = M 3 9 3
103 23 13 mulcomi 2 3 = 3 2
104 103 oveq2i 3 2 3 = 3 3 2
105 expmul 3 2 0 3 0 3 2 3 = 3 2 3
106 13 34 24 105 mp3an 3 2 3 = 3 2 3
107 expmul 3 3 0 2 0 3 3 2 = 3 3 2
108 13 24 34 107 mp3an 3 3 2 = 3 3 2
109 104 106 108 3eqtr3i 3 2 3 = 3 3 2
110 sq3 3 2 = 9
111 110 oveq1i 3 2 3 = 9 3
112 58 oveq1i 3 3 2 = 27 2
113 109 111 112 3eqtr3i 9 3 = 27 2
114 113 oveq2i M 3 9 3 = M 3 27 2
115 102 114 eqtrdi φ M 9 3 = M 3 27 2
116 115 oveq2d φ 4 M 9 3 = 4 M 3 27 2
117 97 116 eqtr4d φ 4 M 3 27 2 = 4 M 9 3
118 117 oveq1d φ 4 M 3 27 2 2 2 = 4 M 9 3 2 2
119 sq2 2 2 = 4
120 119 oveq2i 4 M 9 3 2 2 = 4 M 9 3 4
121 17 98 101 divcld φ M 9
122 expcl M 9 3 0 M 9 3
123 121 24 122 sylancl φ M 9 3
124 4ne0 4 0
125 124 a1i φ 4 0
126 123 89 125 divcan3d φ 4 M 9 3 4 = M 9 3
127 120 126 eqtrid φ 4 M 9 3 2 2 = M 9 3
128 118 127 eqtrd φ 4 M 3 27 2 2 2 = M 9 3
129 87 128 oveq12d φ N 2 27 2 2 2 4 M 3 27 2 2 2 = N 27 2 2 M 9 3
130 41 sqcld φ N 2
131 130 93 96 divcld φ N 2 27 2
132 mulcl 4 M 3 4 M 3
133 88 91 132 sylancr φ 4 M 3
134 133 93 96 divcld φ 4 M 3 27 2
135 23 sqcli 2 2
136 135 a1i φ 2 2
137 119 124 eqnetri 2 2 0
138 137 a1i φ 2 2 0
139 131 134 136 138 divsubdird φ N 2 27 2 4 M 3 27 2 2 2 = N 2 27 2 2 2 4 M 3 27 2 2 2
140 77 sqcld φ N 27 2 2
141 140 123 negsubd φ N 27 2 2 + M 9 3 = N 27 2 2 M 9 3
142 129 139 141 3eqtr4d φ N 2 27 2 4 M 3 27 2 2 2 = N 27 2 2 + M 9 3
143 7 42 44 sqdivd φ G 27 2 = G 2 27 2
144 8 oveq1d φ G 2 27 2 = N 2 4 M 3 27 2
145 130 133 93 96 divsubdird φ N 2 4 M 3 27 2 = N 2 27 2 4 M 3 27 2
146 143 144 145 3eqtrd φ G 27 2 = N 2 27 2 4 M 3 27 2
147 146 oveq1d φ G 27 2 2 2 = N 2 27 2 4 M 3 27 2 2 2
148 oexpneg M 9 3 ¬ 2 3 M 9 3 = M 9 3
149 121 51 53 148 syl3anc φ M 9 3 = M 9 3
150 149 oveq2d φ N 27 2 2 + M 9 3 = N 27 2 2 + M 9 3
151 142 147 150 3eqtr4d φ G 27 2 2 2 = N 27 2 2 + M 9 3
152 82 83 151 3eqtrd φ G 27 2 2 = N 27 2 2 + M 9 3
153 17 18 18 20 20 divdiv1d φ M 3 3 = M 3 3
154 3t3e9 3 3 = 9
155 154 oveq2i M 3 3 = M 9
156 153 155 eqtrdi φ M 3 3 = M 9
157 156 negeqd φ M 3 3 = M 9
158 21 18 20 divnegd φ M 3 3 = M 3 3
159 157 158 eqtr3d φ M 9 = M 3 3
160 eqidd φ N 27 2 = N 27 2
161 5 18 11 20 divne0d φ T 3 0
162 48 161 negne0d φ T 3 0
163 22 45 47 49 79 80 152 159 160 162 dcubic φ X + B 3 3 + M 3 X + B 3 + N 27 = 0 r r 3 = 1 X + B 3 = r T 3 M 9 r T 3
164 binom3 X B 3 X + B 3 3 = X 3 + 3 X 2 B 3 + 3 X B 3 2 + B 3 3
165 4 46 164 syl2anc φ X + B 3 3 = X 3 + 3 X 2 B 3 + 3 X B 3 2 + B 3 3
166 4 sqcld φ X 2
167 18 166 46 mul12d φ 3 X 2 B 3 = X 2 3 B 3
168 1 18 20 divcan2d φ 3 B 3 = B
169 168 oveq2d φ X 2 3 B 3 = X 2 B
170 166 1 mulcomd φ X 2 B = B X 2
171 167 169 170 3eqtrd φ 3 X 2 B 3 = B X 2
172 171 oveq2d φ X 3 + 3 X 2 B 3 = X 3 + B X 2
173 172 oveq1d φ X 3 + 3 X 2 B 3 + 3 X B 3 2 + B 3 3 = X 3 + B X 2 + 3 X B 3 2 + B 3 3
174 165 173 eqtrd φ X + B 3 3 = X 3 + B X 2 + 3 X B 3 2 + B 3 3
175 174 oveq1d φ X + B 3 3 + M 3 X + B 3 + N 27 = X 3 + B X 2 + 3 X B 3 2 + B 3 3 + M 3 X + B 3 + N 27
176 expcl X 3 0 X 3
177 4 24 176 sylancl φ X 3
178 1 166 mulcld φ B X 2
179 177 178 addcld φ X 3 + B X 2
180 46 sqcld φ B 3 2
181 4 180 mulcld φ X B 3 2
182 18 181 mulcld φ 3 X B 3 2
183 expcl B 3 3 0 B 3 3
184 46 24 183 sylancl φ B 3 3
185 182 184 addcld φ 3 X B 3 2 + B 3 3
186 22 47 mulcld φ M 3 X + B 3
187 186 45 addcld φ M 3 X + B 3 + N 27
188 179 185 187 addassd φ X 3 + B X 2 + 3 X B 3 2 + B 3 3 + M 3 X + B 3 + N 27 = X 3 + B X 2 + 3 X B 3 2 + B 3 3 + M 3 X + B 3 + N 27
189 22 4 46 adddid φ M 3 X + B 3 = M 3 X + M 3 B 3
190 189 oveq1d φ M 3 X + B 3 + N 27 = M 3 X + M 3 B 3 + N 27
191 22 4 mulcld φ M 3 X
192 22 46 mulcld φ M 3 B 3
193 191 192 45 addassd φ M 3 X + M 3 B 3 + N 27 = M 3 X + M 3 B 3 + N 27
194 9 oveq1d φ M 3 = B 2 3 C 3
195 12 15 18 20 divsubdird φ B 2 3 C 3 = B 2 3 3 C 3
196 2 18 20 divcan3d φ 3 C 3 = C
197 196 oveq2d φ B 2 3 3 C 3 = B 2 3 C
198 194 195 197 3eqtrd φ M 3 = B 2 3 C
199 198 negeqd φ M 3 = B 2 3 C
200 12 18 20 divcld φ B 2 3
201 200 2 negsubdi2d φ B 2 3 C = C B 2 3
202 199 201 eqtrd φ M 3 = C B 2 3
203 202 oveq1d φ M 3 X = C B 2 3 X
204 2 200 4 subdird φ C B 2 3 X = C X B 2 3 X
205 200 4 mulcomd φ B 2 3 X = X B 2 3
206 13 sqvali 3 2 = 3 3
207 206 oveq2i B 2 3 2 = B 2 3 3
208 1 18 20 sqdivd φ B 3 2 = B 2 3 2
209 12 18 18 20 20 divdiv1d φ B 2 3 3 = B 2 3 3
210 207 208 209 3eqtr4a φ B 3 2 = B 2 3 3
211 210 oveq2d φ 3 B 3 2 = 3 B 2 3 3
212 200 18 20 divcan2d φ 3 B 2 3 3 = B 2 3
213 211 212 eqtrd φ 3 B 3 2 = B 2 3
214 213 oveq2d φ X 3 B 3 2 = X B 2 3
215 4 18 180 mul12d φ X 3 B 3 2 = 3 X B 3 2
216 205 214 215 3eqtr2d φ B 2 3 X = 3 X B 3 2
217 216 oveq2d φ C X B 2 3 X = C X 3 X B 3 2
218 203 204 217 3eqtrd φ M 3 X = C X 3 X B 3 2
219 202 oveq1d φ M 3 B 3 = C B 2 3 B 3
220 2 200 46 subdird φ C B 2 3 B 3 = C B 3 B 2 3 B 3
221 2 1 18 20 divassd φ C B 3 = C B 3
222 2 1 mulcomd φ C B = B C
223 222 oveq1d φ C B 3 = B C 3
224 221 223 eqtr3d φ C B 3 = B C 3
225 12 18 1 18 20 20 divmuldivd φ B 2 3 B 3 = B 2 B 3 3
226 df-3 3 = 2 + 1
227 226 oveq2i B 3 = B 2 + 1
228 expp1 B 2 0 B 2 + 1 = B 2 B
229 1 34 228 sylancl φ B 2 + 1 = B 2 B
230 227 229 eqtr2id φ B 2 B = B 3
231 154 a1i φ 3 3 = 9
232 230 231 oveq12d φ B 2 B 3 3 = B 3 9
233 225 232 eqtrd φ B 2 3 B 3 = B 3 9
234 224 233 oveq12d φ C B 3 B 2 3 B 3 = B C 3 B 3 9
235 219 220 234 3eqtrd φ M 3 B 3 = B C 3 B 3 9
236 10 oveq1d φ N 27 = 2 B 3 - 9 B C + 27 D 27
237 33 39 42 44 divdird φ 2 B 3 - 9 B C + 27 D 27 = 2 B 3 9 B C 27 + 27 D 27
238 28 32 42 44 divsubdird φ 2 B 3 9 B C 27 = 2 B 3 27 9 B C 27
239 9t3e27 9 3 = 27
240 239 oveq2i 9 B C 9 3 = 9 B C 27
241 30 18 98 20 101 divcan5d φ 9 B C 9 3 = B C 3
242 240 241 eqtr3id φ 9 B C 27 = B C 3
243 242 oveq2d φ 2 B 3 27 9 B C 27 = 2 B 3 27 B C 3
244 238 243 eqtrd φ 2 B 3 9 B C 27 = 2 B 3 27 B C 3
245 3 42 44 divcan3d φ 27 D 27 = D
246 244 245 oveq12d φ 2 B 3 9 B C 27 + 27 D 27 = 2 B 3 27 - B C 3 + D
247 236 237 246 3eqtrd φ N 27 = 2 B 3 27 - B C 3 + D
248 235 247 oveq12d φ M 3 B 3 + N 27 = B C 3 B 3 9 + 2 B 3 27 B C 3 + D
249 26 98 101 divcld φ B 3 9
250 28 42 44 divcld φ 2 B 3 27
251 249 250 negsubdi2d φ B 3 9 2 B 3 27 = 2 B 3 27 B 3 9
252 1 18 20 56 expdivd φ B 3 3 = B 3 3 3
253 58 oveq2i B 3 3 3 = B 3 27
254 ax-1cn 1
255 2p1e3 2 + 1 = 3
256 13 23 254 255 subaddrii 3 2 = 1
257 256 oveq1i 3 2 B 3 = 1 B 3
258 26 mulid2d φ 1 B 3 = B 3
259 257 258 eqtrid φ 3 2 B 3 = B 3
260 18 62 26 subdird φ 3 2 B 3 = 3 B 3 2 B 3
261 259 260 eqtr3d φ B 3 = 3 B 3 2 B 3
262 261 oveq1d φ B 3 27 = 3 B 3 2 B 3 27
263 mulcl 3 B 3 3 B 3
264 13 26 263 sylancr φ 3 B 3
265 264 28 42 44 divsubdird φ 3 B 3 2 B 3 27 = 3 B 3 27 2 B 3 27
266 262 265 eqtrd φ B 3 27 = 3 B 3 27 2 B 3 27
267 253 266 eqtrid φ B 3 3 3 = 3 B 3 27 2 B 3 27
268 29 13 239 mulcomli 3 9 = 27
269 268 oveq2i 3 B 3 3 9 = 3 B 3 27
270 26 98 18 101 20 divcan5d φ 3 B 3 3 9 = B 3 9
271 269 270 eqtr3id φ 3 B 3 27 = B 3 9
272 271 oveq1d φ 3 B 3 27 2 B 3 27 = B 3 9 2 B 3 27
273 252 267 272 3eqtrd φ B 3 3 = B 3 9 2 B 3 27
274 273 negeqd φ B 3 3 = B 3 9 2 B 3 27
275 30 18 20 divcld φ B C 3
276 275 249 250 npncan3d φ B C 3 B 3 9 + 2 B 3 27 - B C 3 = 2 B 3 27 B 3 9
277 251 274 276 3eqtr4d φ B 3 3 = B C 3 B 3 9 + 2 B 3 27 - B C 3
278 277 oveq1d φ - B 3 3 + D = B C 3 B 3 9 + 2 B 3 27 B C 3 + D
279 184 negcld φ B 3 3
280 279 3 addcomd φ - B 3 3 + D = D + B 3 3
281 235 192 eqeltrrd φ B C 3 B 3 9
282 250 275 subcld φ 2 B 3 27 B C 3
283 281 282 3 addassd φ B C 3 B 3 9 + 2 B 3 27 B C 3 + D = B C 3 B 3 9 + 2 B 3 27 B C 3 + D
284 278 280 283 3eqtr3d φ D + B 3 3 = B C 3 B 3 9 + 2 B 3 27 B C 3 + D
285 3 184 negsubd φ D + B 3 3 = D B 3 3
286 248 284 285 3eqtr2d φ M 3 B 3 + N 27 = D B 3 3
287 218 286 oveq12d φ M 3 X + M 3 B 3 + N 27 = C X 3 X B 3 2 + D - B 3 3
288 190 193 287 3eqtrd φ M 3 X + B 3 + N 27 = C X 3 X B 3 2 + D - B 3 3
289 2 4 mulcld φ C X
290 289 3 182 184 addsub4d φ C X + D - 3 X B 3 2 + B 3 3 = C X 3 X B 3 2 + D - B 3 3
291 288 290 eqtr4d φ M 3 X + B 3 + N 27 = C X + D - 3 X B 3 2 + B 3 3
292 291 oveq2d φ 3 X B 3 2 + B 3 3 + M 3 X + B 3 + N 27 = 3 X B 3 2 + B 3 3 + C X + D - 3 X B 3 2 + B 3 3
293 289 3 addcld φ C X + D
294 185 293 pncan3d φ 3 X B 3 2 + B 3 3 + C X + D - 3 X B 3 2 + B 3 3 = C X + D
295 292 294 eqtrd φ 3 X B 3 2 + B 3 3 + M 3 X + B 3 + N 27 = C X + D
296 295 oveq2d φ X 3 + B X 2 + 3 X B 3 2 + B 3 3 + M 3 X + B 3 + N 27 = X 3 + B X 2 + C X + D
297 175 188 296 3eqtrd φ X + B 3 3 + M 3 X + B 3 + N 27 = X 3 + B X 2 + C X + D
298 297 eqeq1d φ X + B 3 3 + M 3 X + B 3 + N 27 = 0 X 3 + B X 2 + C X + D = 0
299 oveq1 r = 0 r 3 = 0 3
300 0exp 3 0 3 = 0
301 50 300 ax-mp 0 3 = 0
302 299 301 eqtrdi r = 0 r 3 = 0
303 0ne1 0 1
304 303 a1i r = 0 0 1
305 302 304 eqnetrd r = 0 r 3 1
306 305 necon2i r 3 = 1 r 0
307 eqcom X = B + r T + M r T 3 B + r T + M r T 3 = X
308 1 adantr φ r r 0 B
309 simprl φ r r 0 r
310 5 adantr φ r r 0 T
311 309 310 mulcld φ r r 0 r T
312 17 adantr φ r r 0 M
313 simprr φ r r 0 r 0
314 11 adantr φ r r 0 T 0
315 309 310 313 314 mulne0d φ r r 0 r T 0
316 312 311 315 divcld φ r r 0 M r T
317 311 316 addcld φ r r 0 r T + M r T
318 13 a1i φ r r 0 3
319 19 a1i φ r r 0 3 0
320 308 317 318 319 divdird φ r r 0 B + r T + M r T 3 = B 3 + r T + M r T 3
321 308 311 316 addassd φ r r 0 B + r T + M r T = B + r T + M r T
322 321 oveq1d φ r r 0 B + r T + M r T 3 = B + r T + M r T 3
323 46 adantr φ r r 0 B 3
324 317 318 319 divcld φ r r 0 r T + M r T 3
325 323 324 subnegd φ r r 0 B 3 r T + M r T 3 = B 3 + r T + M r T 3
326 320 322 325 3eqtr4d φ r r 0 B + r T + M r T 3 = B 3 r T + M r T 3
327 326 negeqd φ r r 0 B + r T + M r T 3 = B 3 r T + M r T 3
328 324 negcld φ r r 0 r T + M r T 3
329 323 328 negsubdi2d φ r r 0 B 3 r T + M r T 3 = - r T + M r T 3 - B 3
330 327 329 eqtrd φ r r 0 B + r T + M r T 3 = - r T + M r T 3 - B 3
331 330 eqeq1d φ r r 0 B + r T + M r T 3 = X - r T + M r T 3 - B 3 = X
332 307 331 syl5bb φ r r 0 X = B + r T + M r T 3 - r T + M r T 3 - B 3 = X
333 4 adantr φ r r 0 X
334 328 323 333 subadd2d φ r r 0 - r T + M r T 3 - B 3 = X X + B 3 = r T + M r T 3
335 311 316 318 319 divdird φ r r 0 r T + M r T 3 = r T 3 + M r T 3
336 335 negeqd φ r r 0 r T + M r T 3 = r T 3 + M r T 3
337 311 318 319 divcld φ r r 0 r T 3
338 316 318 319 divcld φ r r 0 M r T 3
339 337 338 negdi2d φ r r 0 r T 3 + M r T 3 = - r T 3 - M r T 3
340 309 310 318 319 divassd φ r r 0 r T 3 = r T 3
341 340 negeqd φ r r 0 r T 3 = r T 3
342 48 adantr φ r r 0 T 3
343 309 342 mulneg2d φ r r 0 r T 3 = r T 3
344 341 343 eqtr4d φ r r 0 r T 3 = r T 3
345 312 311 318 315 319 divdiv32d φ r r 0 M r T 3 = M 3 r T
346 21 adantr φ r r 0 M 3
347 346 311 318 315 319 divcan7d φ r r 0 M 3 3 r T 3 = M 3 r T
348 156 oveq1d φ M 3 3 r T 3 = M 9 r T 3
349 348 adantr φ r r 0 M 3 3 r T 3 = M 9 r T 3
350 345 347 349 3eqtr2d φ r r 0 M r T 3 = M 9 r T 3
351 121 adantr φ r r 0 M 9
352 311 318 315 319 divne0d φ r r 0 r T 3 0
353 351 337 352 div2negd φ r r 0 M 9 r T 3 = M 9 r T 3
354 344 oveq2d φ r r 0 M 9 r T 3 = M 9 r T 3
355 350 353 354 3eqtr2d φ r r 0 M r T 3 = M 9 r T 3
356 344 355 oveq12d φ r r 0 - r T 3 - M r T 3 = r T 3 M 9 r T 3
357 336 339 356 3eqtrd φ r r 0 r T + M r T 3 = r T 3 M 9 r T 3
358 357 eqeq2d φ r r 0 X + B 3 = r T + M r T 3 X + B 3 = r T 3 M 9 r T 3
359 332 334 358 3bitrrd φ r r 0 X + B 3 = r T 3 M 9 r T 3 X = B + r T + M r T 3
360 359 anassrs φ r r 0 X + B 3 = r T 3 M 9 r T 3 X = B + r T + M r T 3
361 306 360 sylan2 φ r r 3 = 1 X + B 3 = r T 3 M 9 r T 3 X = B + r T + M r T 3
362 361 pm5.32da φ r r 3 = 1 X + B 3 = r T 3 M 9 r T 3 r 3 = 1 X = B + r T + M r T 3
363 362 rexbidva φ r r 3 = 1 X + B 3 = r T 3 M 9 r T 3 r r 3 = 1 X = B + r T + M r T 3
364 163 298 363 3bitr3d φ X 3 + B X 2 + C X + D = 0 r r 3 = 1 X = B + r T + M r T 3